REICHERT, KARL BOGISLAUS

(b. Rastenburg, East Prussia [now Ketrzyn, Poland], 20 December 1811; d. Berlin, Germany, 21 December 1883)

comparative anatomy, histology, embryology.

Reichert made very important contributions to the knowledge of transformations of early structures during the embryo’s development and to the understanding, from a comparative point of view, of the development of an individual organism. He also played an important role as editor of the leading German anatomical periodical. In his last years, however, his prestige diminished because of his opposition to the new biological theories.

Reichert’s father, mayor of Rastenburg, died on the day his son was born. The boy’s stepfather, a high school principal, saw to it that he had a good education. Reichert began the study of medicine at Königsberg, where K.E. von Baer aroused his interest in embryology. He soon went to Berlin, however, to continue his education at the military medical school(Friedrich-Wilhelm-Institut) and at the University of Berlin, where he became the protégé of Friedrich Schlemn and Johannes Müllar. He graduated in 1836 with a dissertation on the gill arches of the vertebrate empryos. Alexander von Humboldt secured him a leave for scientific work and eventually freedom from his military obligations. As prosector of anatomy in Mullar’s department, Reichert was very active both in research and in preparing an annual review of histology for the Archiv für Anatomie. In 1843 he was called to the University of Dorpat as professor of anatomy. Ten years later he became professor of physiology at Breslau, succeeding K. T. E. von Siebold. After the death of Müllar in 1858, Reichert occupied the chair of anatomy and remained in Berlin for the rest of his life.

Reichert’s greatest accomplishment was the introduction into embryology of the cell theory soon after its formulation by Schwann. Studying the evolution of frog spawn, he described with great accuracy the consecutive stages of its development, demonstrating that globules formed during the segmentation of the vitellus are cells and that all subsequent parts of the embryonic organs derive from the cleavage cells of the embryo. Like other biologists, however, Reichert erroneously believed that the granules in the yolk of the egg also were individual cells. On the other had, he carefully distinguished the formative and the nutritive parts of the yolk, calling them Bildungsdotter and Nahrungsdotter. He also mads valuable observations on the evolution of the tadpole, especially of the head, and presented many general reflections on the formation of different structures by means of invagination which foreshadowed, to some degree, Haeckel’s gastraea theory.

Reichert’s discovery of true homologies between the middle-ear ossicles and primitive structures of the splanchnocranium of reptiles and other lower verteberates has found all the intermediary stages that Reichert had envisaged. This was a brilliant linking of embryology with comparative anatomy and physiology, an example of transformation of the original structure connected to a change of function. Another of Reichert’s great contributions was his demonstration that all types of connective tissue are closely related, have many common features, and derive from the same primary structures.

In his last years Reichert, holder of a very important Chair and editor of a major periodical, and thus formally a leader in his field, became completely isolated because of his stubborn opposition to Haeckel’s theory of the homology of germinal layers throughout the animal kingdom, the concept of protoplasm and new developments of the cell theory, and Drawin’s theory of the origin of species.

BIBLIOGRAPHY

I. Original Works. Reichert’s works include De embryonum arcurabus sic dictis branchialibus (Berlin, 1836); Ueber die Visceralbogen der Wirbeltheiere im Allgemeinen und deren Metamorphose bei Säugetheieren und Vögeln (Berlin, 1837); Vergleichende Entwicklungsgeschichte des Kopfes der nackten Amphibien (Köngisberg, 1838); “Kritische Jahresberichte über die Fortschritte der mikroskopischen Antomie,”, in Archiv fur Anatomie, Physiologie und wissenschaftlilche Medizin (1839–1858); Das Entwicklungsleben im Wirbeltheierreiche (Berlin, 1840); Beitäge zur Kenntniss des Zustandes der heutigen Ebtwickungs geschichte (Berlin, 1843); Über die Entwicklung des befruchteten Säugetheiueries (Berlin, 1843); Bemerkungen zur verglgicheden Naturforschung im Allgemeinen und die verwandten Gebilde (Dorpat, 1845);Die monogene Fortpflanzung (Dorpat, 1852); Der Bau des menschlichen Gehirns, 2 vols. (Leizig, 1859–1861); Beitrag zur feineren Anatomie der Gehörschnecke des Menschen und der Säugethiere (Berlin, 1864); and “Beschreibung einer frühzeitigen menschlichen Frucht im bläschenförmingen Bildungszustande nebst vergleicheden Untersuchungen uber die blaschenformigen Fruchted der Saugethered und des Menschen’,s in abhabdlungen der Preussichen Akade mied der Wissenschaften (1873), a description of a 12-day-old human embryo, the earliest know at that time.

II. Secondary Literature. [G.] Br[oesike], “Carl Bogislaus Reicher,” in Berliner klinische wochenschrift (1884), 45–46; J. Page, “Reichert, Karl Bogislaus’, in Allgemeine deutsche Biographie, XXVII (1888), 679–681; and Waldeer, in Biographisches Lexikonn der hervoragenden Ärzte aller Zeiten und Völker, IV (Berlin-Vienna, 1932), 752–753.

Vladislav Kruta